Oil control valve

ABSTRACT

As an oil control valve controlling oil pressure of a first hydraulic pressure chamber and a second hydraulic pressure chamber formed inside of a first electric hydraulic valve (EHV) device and a second EHV device, respectively, which are driven by a first cam and a second cam and include lower parts to which a first valve and a second valve are respectively connected, the oil control valve includes: a body including a communication hole having a first end in communication with the first hydraulic pressure chamber and a second end in communication with the second hydraulic pressure chamber; a hollow lower frame formed or fixedly mounted at the lower end part of the body and having an upper part communicating with the communication hole and a lower part communicating with an oil gallery supplying oil by disposing an upper end height at an inner space of the communication hole; and a pin frame disposed between an actuator moving up and down and the lower frame so as to vertically penetrate the communication hole and in contact with or separated from the upper part of the lower frame, wherein one end and the other end of the communication hole are in communication when the pin frame and the lower frame are in contact.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2018-0159341 filed in the Korean IntellectualProperty Office on Dec. 11, 2018, the entire contents of which areincorporated herein by reference.

BACKGROUND (a) Field of Disclosure

The present disclosure relates to an oil control valve (OCV). Moreparticularly, the present disclosure relates to an oil control valvethat prevents an occurrence of lift deviations between two valves of thesame type.

(b) Description of the Related Art

A variable valve control technology is one field for improvingefficiency of automobile engines.

Generally, intake and exhaust of an engine are controlled by adjustingopening and closing timing of valves by a shape of a cam and a phasedifference between the cams.

A variable valve timing (VVT) means adjusts the opening and closingtiming of the valves to control an overlap section in which an intakevalve and an exhaust valve are simultaneously open, and a variable valvelift (VVL) means adjusts a valve lift to control an intake air amount.

As the VVT means evolved into a continuous variable valve timing (CVVT)means, the VVL means evolved into a continuous variable valve lift(CVVL) means, and a mechanical electric hydraulic valve train (MEHV)means has been developed and actively applied to a vehicle engine.

The MEHV means is a combination of a mechanical valve mechanism and anelectric hydraulic valve (EHV), and controls the valve lift by using oilpressure.

Generally, the MEHV system operates two electric hydraulic valve (EHV)devices having the same structure, and two valves of the same type(intake or exhaust) respectively connected to the above-describeddevices by using one oil control valve (OCV).

The EHV device is generally driven by a mechanical cam, and a hydraulicpressure chamber is formed in the EHV device, and as the oil is suppliedto the hydraulic pressure chamber through the OCV or the oil isdischarged from the hydraulic pressure chamber, the driving effect bythe cam is controlled. That is, if the cam drives the EHV device in thestate in which sufficient oil is supplied to the EHV device, the valveconnected to the EHV device operates, resulting in the valve lift.However, if the cam drives the EHV device in a state in which the oil isdrained from the EHV device, the valves connected to the EHV device donot work.

The conventional MEHV systems use the OCV configured to allow two EHVdevices to communicate with each other for smooth supply of the oil.Therefore, when there is an oil pressure difference between the two EHVdevices, oil pulsation may occur between the two EHV devices, and as aresult, a lift deviation occurs between the two valves respectivelyconnected to two EHV devices.

FIG. 5 is a graph showing a valve lift according to a cam angle when aconventional oil control valve is applied.

Referring to FIG. 5, the lift deviation appears between the left andright valves. In this state, an imbalance of combustions of the enginecylinders may occur, and the fuel consumption, emission, or knockingcharacteristics may deteriorate.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention andtherefore it may contain information that does not form the prior artthat is already known in this country to a person of ordinary skill inthe art.

SUMMARY

The present disclosure provides an oil control valve for preventing alift deviation between two valves.

An oil control valve controlling oil pressure of a first hydraulicpressure chamber and a second hydraulic pressure chamber formed insideof a first electric hydraulic valve (EHV) device and a second EHVdevice, respectively, which are driven by a first cam and a second camand include lower parts to which a first valve and a second valve arerespectively connected, may include a body including a communicationhole having a first end in communication with the first hydraulicpressure chamber and a second end in communication with the secondhydraulic pressure chamber; a hollow lower frame formed or fixedlymounted at the lower end part of the body and having an upper partcommunicating with the communication hole and a lower part communicatingwith an oil gallery supplying oil by disposing an upper end height at aninner space of the communication hole; and a pin frame disposed betweenan actuator moving up and down and the hollow lower frame so as tovertically penetrate the communication hole and in contact with orseparated from the upper part of the lower frame, wherein each end ofthe communication hole are not communicated when the pin frame and thehollow lower frame are in contact.

The pin frame may be hollow, and the oil control valve may furtherinclude a spring acting as a restoring force to the pin frame as theupper end is connected to the upper part of the pin frame and the lowerend is connected to a supporting part formed at an inner space of thelower frame.

The actuator may be operated up and down by a solenoid.

The pin frame may be integrally formed with the lower end part of theactuator.

The lower frame, the communication hole, and the pin frame may each havea cylinder shape, and a diameter of the lower frame and the pin framemay be larger than a diameter of the communication hole.

A chamfer may be formed along an external circumference surface of thelower end of the pin frame in the pin frame, and a chamfer surface maybe formed at the upper end of the lower frame so as to maintain a fixedand air-tight state by meeting the chamfer.

In the oil control valve according to an exemplary embodiment of thepresent disclosure, when the pin frame is separated from the lowerframe, as the oil is drained from the first EHV device and the secondEHV device, the first valve and the second valve may not be operateddespite the operation of the first cam and the second cam.

In the oil control valve, when the pin frame is in contact with thelower frame, the first valve and the second valve may be operated by theoperation of the first cam and the second cam.

As described above, according to the present disclosure, since the liftprofiles between the two valves are equal to each other, the fuelefficiency and the emission may be improved, and the occurrence ofknocking may be reduced.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram of a valve train structure mounted with anoil control valve according to an exemplary embodiment of the presentdisclosure.

FIG. 2 is a side view of a valve train structure mounted with an oilcontrol valve according to an exemplary embodiment of the presentdisclosure.

FIG. 3 is a cross-sectional view along a line A-A of an oil controlvalve according to an exemplary embodiment of the present disclosure.

FIG. 4 is a cross-sectional view along a line B-B of an oil controlvalve according to an exemplary embodiment of the present disclosure.

FIG. 5 is a graph showing a valve lift according to a cam angle when aconventional oil control valve is applied.

FIG. 6 is a graph showing a valve lift according to a cam angle when anoil control valve according to an exemplary embodiment of the presentdisclosure.

DETAILED DESCRIPTION

The present disclosure will be described more fully hereinafter withreference to the accompanying drawings, in which an exemplary embodimentof the disclosure is shown.

The exemplary embodiment is an example of the present disclosure and canbe modified in various ways by those skilled in the art, so the scope ofthe present disclosure is not limited to the exemplary embodiment to bedescribed below.

Through the present specification, unless explicitly describedotherwise, “including” any components will be understood to imply theinclusion of other components but not the exclusion of any othercomponents. Further, the names of the components do not limit theirfunction.

FIG. 1 is a schematic diagram of a valve train structure mounted with anoil control valve according to an exemplary embodiment of the presentdisclosure.

FIG. 2 is a side view of a valve train structure mounted with an oilcontrol valve according to an exemplary embodiment of the presentdisclosure.

Referring to FIG. 1 and FIG. 2, an oil control valve 10 according to anexemplary embodiment is configured to control oil pressure of a firsthydraulic pressure chamber 21 a and a second hydraulic pressure chamber22 a formed inside of a first electric hydraulic valve (EHV) device 21and a second EHV device 22, respectively. The first EHV device 21 andthe second EHV device 22 are driven by a first cam 1 and a second cam 2,respectively, and a first valve 3 and a second valve 4 are connected tothe lower parts thereof, respectively. Therefore, the operation of thefirst valve 3 and the second valve 4 is controlled by the oil controlvalve 10.

The oil control valve 10 may include a body 30 having a communicationhole 312 including a first end 31 communicating with the first hydraulicpressure chamber 21 a and a second end 32 communicating with the secondhydraulic pressure chamber 22 a. The body 30 further includes a hollowlower frame 40 formed or fixedly mounted at the lower end part of thebody 30, and having an upper part communicating with the communicationhole 312. A lower part of the body 30 communicates with an oil gallery34 supplying oil by disposing an upper end height at an inner space ofthe communication hole 312. A pin frame 50 is disposed between anactuator 15 moving up and down and the lower frame 40 so as tovertically penetrate the communication hole 312 and in contact with orseparated from the upper end of the lower frame 40.

The oil control valve 10 is configured so that the first and second ends31, 32 of the communication hole 312 do not communicate with each otherwhen the pin frame 50 and the lower frame 40 are in contact with eachother. That is, the ends are blocked by the lower frame 40 and the pinframe 50.

To this end, the lower frame 40, the communication hole 312, and the pinframe 50 may have a cylinder shape, and the lower frame 40 and the pinframe 50 may have a greater diameter than the diameter of thecommunication hole 312. However, the exemplary embodiment is not limitedthereto, and in the contact between the lower frame 40 and the pin frame50, as long as the lower frame 40 and the pin frame 50 block the insideof the communication hole 312 so that the first and second ends 31, 32of the communication hole do not communicate with each other, anystructure is allowed.

The first hydraulic pressure chamber 21 a and the first end 31 of thecommunication hole 312 may communicate by way of a left pipe 5 and thesecond hydraulic pressure chamber 22 a, and the second end 32 of thecommunication hole 312 may be communicated by way of a right pipe 6. Inthis case, the left and right pipes 5 and 6 may be formed in a cylinderhead 7. The oil control valve 10 is typically mounted on the cylinderhead 7.

The mechanism by which the first and second hydraulic pressure chambers21 a and 22 as are formed in the first and second EHV devices 21 and 22,respectively, are well known to those skilled in the art and thus thedetailed description is omitted.

When the pin frame 50 is separated from the upper end of the lower frame40, the first and second EHV devices 21 and 22 may communicate with eachother through the first and second hydraulic pressure chambers 21 a and22 a, the right and left pipes 5 and 6, and the communication hole 312.

Also, referring to FIG. 2, the valve train structure mounted with theoil control valve 10 according to an exemplary embodiment may furtherinclude an accumulator 25 formed in the cylinder head 7. In this case,when the oil control valve 10 is open, that is, when the pin frame 50 isseparated from the lower frame 40, the valve train structure may beformed so that the oil in the first and second EHV devices 21 and 22 maybe accumulated in the accumulator 25. By the oil flow to the accumulator25, the first and second valves 3 and 4 are closed despite the actionsof the first and second cams 1 and 2.

Referring to FIG. 1, in the oil control valve 10 according to anexemplary embodiment, the pin frame 50 may be hollow. Also, the oilcontrol valve 10, as the upper end is connected to the upper part of thepin frame 50 and the lower end is connected to a supporting part 35formed in the inner space of the lower frame 40, may further include aspring 60 acting as a restoring force to the pin frame 50.

The actuator 15, which is disposed within the oil control valve 10, maybe operated up and down by the solenoid. In this case, when the currentis applied to the oil control valve 10, the actuator 15 is operated upor down.

Thus, when the actuator 15 is operated downward and the pin frame 50 isin contact with the lower frame 40, the spring 60 may be compressed, andwhen the actuator 15 is actuated upward so that the pin frame 50 isseparated from the lower frame 40, the spring 60 may be extended. Whenthe current applied to the oil control valve 10 is disconnected, the pinframe 50 may be returned to its initial position by the restoring forceof the compressed or extended spring 60.

The pin frame 50 may be integrally formed with the lower end of theactuator 15, but it is not necessarily so. The pin frame 50 may be apart that is separate from the actuator 15. The pin frame 50 may beselectively in contact with or separated from the lower frame 40 by theactuator 15 and the spring 60.

FIG. 3 is a cross-sectional view of along a line A-A of an oil controlvalve according to an exemplary embodiment of the present disclosure.

FIG. 4 is a cross-sectional view of along a line B-B of an oil controlvalve according to an exemplary embodiment of the present disclosure.

Referring to FIG. 3 and FIG. 4, in the oil control valve 10 according toan exemplary embodiment of the present disclosure, a chamfer 52 may beformed along an external circumference surface of the lower end of thepin frame 50 in the pin frame 50, and a chamfer surface 42 may be formedat the upper end of the lower frame 40 so as to maintain the fixed andair-tight condition by meeting the chamfer 52. The combination of thechamfer 52 and the chamfer surface 42 may ensure completion of thefixing state of the pin frame 50 and the lower frame 40 and theair-tight state between the first end 31 and the second end 32 of thecommunication hole 312.

FIG. 3 and FIG. 4 both show the state in which the lower frame 40 andthe pin frame 50 are separated from each other. The oil may be suppliedto the first and second EHV devices 21 and 22 through this separationgap and the communication hole 312, or the oil may be drained from thefirst and second EHV devices 21 and 22 to the accumulator 25.

Referring to FIG. 1, FIG. 3, and FIG. 4, the oil control valve 10according to an exemplary embodiment of the present disclosure isconfigured so that the first valve 3 and the second valve 4 are notoperated despite the operation of the first cam 1 and the second cam 2as the oil is drained from the first EHV device 21 and the second EHVdevice 22 when the pin frame 50 is separated from the lower frame 40.

The oil control valve 10 is configured so that the first valve 3 and thesecond valve 4 are operated by the operation of the first cam 1 and thesecond cam 2 when the pin frame 50 is in contact with the lower frame40.

FIG. 6 is a graph showing a valve lift according to a cam angle when anoil control valve according to an exemplary embodiment of the presentdisclosure.

Referring to FIG. 6, if the oil control valve 10 is used, it may beconfirmed that the lift of the first and second valves 3 and 4 issubstantially coincident. This is because the first and second EHVdevices 21 and 22 communicate with each other when the communicationhole 312 is not blocked by the lower frame 40 and the pin frame 50 suchthat the pressure becomes equal, and the first and second EHV devices 21and 22 are fluidly separated from each other and operate independentlyat the same pressure in case of the blocking.

While this disclosure has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the disclosure is not limited to the disclosedembodiments. On the contrary, it is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. An oil control valve controlling oil pressure of a first hydraulicpressure chamber and a second hydraulic pressure chamber formed insideof a first electric hydraulic valve (EHV) device and a second EHVdevice, respectively, which are driven by a first cam and a second camand include lower parts to which a first valve and a second valve arerespectively connected, comprising: a body including a communicationhole having a first end in communication with the first hydraulicpressure chamber and a second end in communication with the secondhydraulic pressure chamber; a hollow lower frame formed or fixedlymounted at a lower end part of the body, the hollow lower frame havingan upper part communicating with the communication hole and a lower partcommunicating with an oil gallery supplying oil by disposing an upperend height at an inner space of the communication hole; and a pin framedisposed between an actuator moving up and down and the hollow lowerframe so as to vertically penetrate the communication hole and incontact with or separated from the upper part of the hollow lower frame,wherein the first end and the second end of the communication hole arenot communicated with each other when the pin frame and the hollow lowerframe are in contact with each other.
 2. The oil control valve of claim1, wherein the pin frame is hollow, and the oil control valve furtherincludes a spring acting as a restoring force to the pin frame as theupper end is connected to an upper part of the pin frame and the lowerend is connected to a supporting part formed at an inner space of thehollow lower frame.
 3. The oil control valve of claim 1, wherein theactuator is operated up and down by a solenoid.
 4. The oil control valveof claim 1, wherein the pin frame is integrally formed with the lowerend part of the actuator.
 5. The oil control valve of claim 1, whereinthe hollow lower frame, the communication hole, and the pin frame eachhave a cylinder shape, and a diameter of the hollow lower frame and thepin frame is larger than a diameter of the communication hole.
 6. Theoil control valve of claim 1, wherein a chamfer is formed along anexternal circumference surface of a lower end of the pin frame in thepin frame, and a chamfer surface is formed at the upper end of the lowerframe so as to maintain a fixed and air-tight state by meeting thechamfer.
 7. The oil control valve of claim 1, wherein when the pin frameis separated from the lower frame, as the oil is drained from the firstEHV device and the second EHV device, the first valve and the secondvalve are not operated despite the operation of the first cam and thesecond cam.
 8. The oil control valve of claim 1, wherein when the pinframe is in contact with the hollow lower frame, the first valve and thesecond valve are operated by the operation of the first cam and thesecond cam.